Electronic translating device



Sgpt. 12, 1950 J. c. O'BRIEN 2, ,0

ELECTRONIC TRANSLATING DEVICE Filed Dec. 31, 1945 's Shegts-Sheet 1Frequency Multiplier Harmonic Generator J H15 ATTORNEY Sept. 12, 1950 J.c, 'BREN 2,522,055

ELECTRONIC TRANSLATING DEVICE Filed Dec. 51-, 1945 v s sh eetse-sheet. 2

Fl G020 $35 BN2 41 Freuency AC Multipl r Harmonia Genera-tor qm w AMultiplier or Harmonic Generator H15 ATTORNEY Frequency AC 64 MultiplierE Harmonic 5 v Generator I J. C. OBRIEN ELECTRONIC TRANSLATING DEVICESept. 12, 1950 3 Sheets-Sheet 5 Filed Dec. 31, 1945 2 OIIIYVENTQRQ I WM.m

ms ATTORNEY Patented Sept. 12 1950 ELECTRONIC 'rasivsts rnve nsv os JohnO. O'Brien, Rochester; N. Y., assignor to General Railway. SignalCompany, Rochester,

Application December 31, 1945, Serial No. 638,546

Claims. (01; sis-21) This invention relates to an electron tube of therotating electron beam type and more particularly to means for variablyrotating and variably focusing its beam during such rotation so that thebeam will move quickly from anode to anode and will hesitate while onsuch anode orplate.

Rotating electron beam type tubes, such as disclosed in the SkelletPatent No. 2,217,774 may be used to perform various kinds ofcommunicating and commutating functionsat high speed. Since no usefulfunction can be performed and no electrons should flow from cathode toanode while the electron beam. moves from one anode to another anodeitis desirable to perform the beam shifting function between plates very.

quickly.

In accordance with the presentinvention it is proposed to provideelectromagnetic means for concentrating the electrons emitted, by thecathode of the tube into a comparatively narrow beam,

and to cause rotation of such electron beam by causing rotation of themagneticfield which'concentrates the electrons into the narrow beam.Since rotating electron beam tubes of the type under considerationpreferably employ more than two anodes it is difiicultto get slowmovement of the rotating magnetic field while the electron beam is on ananode and fast rotation of such electron beam while it is shifting fromone anode to another by the wave form of the fundamental wave of thealternating current, and'it has been found necessary to superimpose uponthefundamental frequency usecl'for rotating the electron beam a higherfrequency wave, the frequency of which higher frequency wave has somerelationship to fundamental frequency and to the number of anodesequally spaced about the cathode of the tube, and in accordance with thepresent invention it is proposed to combine alternating currents of twofrequencies or combine alternating current magnetic fields of twofrequencies in a manner to produce step-by-step rotation of the magneticfield and the electron beam rotated thereby.

In accordance with one form invention it is proposed'to use a laminatediron stator and to wind two difierent windings thereon and energizethese windings with alternating currents, one of which has a frequencywhich is a multiple of the frequency of the other.

In accordance with another form of the present invention it is proposedto use. alternatin current voltages of different :frequenciesin seriesor in multiple with each other and apply them to the same windingtaproduce a stemby-step of the present;

rotating magnetic field,

this being accomplished either by employing the two alternating currentvoltages in series, by employing the two alternating current voltages inmultiple before. phase splitting of such voltages has been accomplished,or by connecting these voltages in series or-mu'ltiple after such phasesplitting has been accomplished to produce a rotating magnetic field oithe step-by-step type. 1 {It has been observed that the ratio of the frequencies of the two alternating currents employed isnot directlyproportional to the number of anodes employed in'the tube but isproportional to either the sum of the anodes plus one" or the sum of theanodes minus one, de-

pending upon whether the supplementalor high frequencymagnetic fleld'isrotated in the same or the reverse direction as the fundamentalfrequency field is rotated.

Another feature of the present invention resides in the provision of asuppressing screen which hasappli'ed thereto alternating currentpotentialsjtofsuppress one end of the double electron beam that'isinherently produced by th V rotatingmagnetic field above mentioned.

'Other objects, purposes and characteristicfeatures of the presentinvention will in p'artbe pointed out in the specification hereinafterand will in part be obvious from. the accompanying drawings in which: W

s Fig. 1 illustrates an arrangement wherein'magnetic fields of differentfrequencies are combined to produce a step-by-step rotating magneticfield;

Fig. 2 illustrates a, modified form of the p ies- ;ent invention inwhich two alternating currents ofdifierent frequencies are applied tothe same phase splitting network which is in turn connected to a singlepolyphase winding to produce a step-,by-step rotating magnetic field;

Fig. 3 illustrates a modification of the form of invention illustratedin Fig. 2 in that the stator structure is somewhat diiierent and in thatthe two alternating current voltages of diiferentfre- .quenoies' areincluded in series whereas in Fig. 2 they are included in multiple;

Fig. 4 illustratesa modified form of the invention illustrated in Figs.-1 and 2 and in this case each of the two alternating currentfrequencieshas itsown phase splitting network as inFig. .1 and: these networks arethen connected in multiple to polyphase windings such as illustrated inFig. 2.

Fig.1 fi'illustrates vectorially and graphically the manner in whichtheelectromagnetic field --the 'same extent.

' 3 rotates when the higher frequency is equal to the lower frequencymultiplied by the number of anodes plus one and when both vectors rotatein a clock-wise direction as is the case in the specific circuitarrangement shown in Figs. 1 and 4; and

Fig. 6 illustrates vectorially and graphically the manner. in which therotatingmagnetic field performs it's"rotating: and hesitating functionwhen the higher frequency is equal to the lower frequency multiplied bythe number of anodes minus one and when these vectors rotate indifferent directions as is true of the forms 'ofinvention illustrated inFigs. 2 and 3 where the two rotating vectors rotate in oppositedirections.

StructureFig. 1.--Referring to Fig. 1 the roth e two alternating-===- Vforces' and the resultin riagiietic fields rotate in two magnetic fieldsthus rotate in opposite directions. Since however the field produced bywinding H is dominant the net rotation of the field is in a clockwisedirection.

Since the particular embodiment of the invention shown in Fig. 1 employsan electron tube having four equally spaced anodes P and since urrentmagnetomotive opposite directions it is essential that the highfrequency current produced by the frequency tating beam electron tube ofthe present invention comprises a cylindrical envelope or tube [0preferably constructed of glass which :is highlyevacuated and contains acathode Ca, a plurality :of anodes P each anode of which is providedwith asuppression grid Gs and each tube is' preferably provided with asingle control grid Gc although a separate control grid for each anodemaybe employed if desired. This-tube I0 is surrounded by an iron statorISI preferably built up from laminations of extremely small thick-.nesses of low hysteretic loss material so as to reduce the eddy currentlosses and allow high frequency magnetomotive forces to be set uptherein. This stator ISI is preferably circular with suitable windingsthereon and is of a size to just barely receive the electron tube l0 andthis stator 'is so constructed that internal rather than externalmagnetic poles are produced therein. As shown in Fig. 1 this stator ISIcomprises a stator of the Gramme type on which two separate andcontinuous windings are placed. The winding H has been shown by heavylines and the winding l2 has been shown 'by light lines although inpractice the wire sizes may be "substantially the same. As illustratedthe heavy winding l l is energized from an alternating current generatorAC through the medium of a phase shifting network including condensersCl and C2 and resistance units RI and R2. The "condenser Cl and theresistance unit RI have such electrical values that the potentialappliedto the point 55 lags the potential applied to the point 14 bysubstantially 90 electrical degrees and the condenser 02 and resistanceunit R2 have electrical constants such as to cause the potential at thepoint I! to lag the potential at the point 56 in phase relationship toan extent of substantially 90.

Inorder to cause the rotating magnetic field of the higher frequencysupplied by the frequency multiplier FM! to rotate in the oppositedirection the phase shifting network 03, R3, C4, R4 have been inverselyarranged as illustrated in Fig. 1. As a result of this reversal ofelements the potential applied to the point 25 of the winding [2 lagsthe voltage applied to the point 26 on this winding to an extent ofsubstantially 90 electrical degrees and likewise the voltage applied atthe point 27 of this winding 12 lags the voltage applied to the point 24to substantially The voltages applied to the points [6 and 26 of thewindings H and-l2 are "respectively of inverse potential to. that 'ofthe points l4 and 24 respectively. In other words, the'rotating magneticfield producedby winding ll rotates in a clockwise direction whereas thefrotating magnetic field producedbywinding l2 -rotates in-acounter-clockwise direction. The

.multiplier PM! he of a frequency which is three "times that of thefrequency of the alternating current. plOdllCEdbY the generator AC andit is :proposed'thatthe frequency multiplier FMI be constructed tperform a frequency tripling function. Thefundamental frequency currentmay be of any desired frequency within limits permitted by eddy currentand hysteretic losses.

Operation--Fig. 1.-%Referring to Fig. 6 of the drawings; let us assume:thatthe magnetomotive force vectori28 is the.magnetomotiveyforceproduced by the-voltage producedbythe generator AC (Fig. '1) andthatthe-magnetomotiveforce vector 29 is produced-:by current derivedfrom the frequency multiplieriFMl 'andthat at during the particularinstant under-consideration these .two voltagesare-in phase 'asillustrated in Fig; 6. .Let us now assumerthat the low: frequencyvoltage'vectorshifts to theflpositionml to: trace the right another 30from the position Silto the position 32, the high speed'voltage' vector"shifts counter-clockwise another as .illustratewby the magneto-motiveforceyector line 33 11h "other' rdSQdu'ring this'30" smaof thefundamental magnetomotive force vector the combined resultofthe'two'magnetomotive force vectors has shifted the entire magnetic'field to'an extentiof substantially or slightly in'excess of 9'0" whilethe fundamental magneto-motive force only shifted to an"exteht oflso".Inlo'therword sltifie rotating magnetic field stood.substantially-stillduring a 60". shift o i .the fundam'ental=magnetomotive force and thenmadeza rushing sweepof substantially a 90.1shiftr duringa 30? lsh rtlorthe fundamentalmagnetiofield. It is,-thus seen that the magnetic fleldrotates step-by step in ;ashigh as is.thedowersfrequency and-the resultsaccomplished by the construction illustrated in Fig. .1 and graphically-analyzed .in Fig. 6 lends itself admirably :rtO .the employment ;offour zanodes in an electron ztube surrounded by :the

rotating magnetic .field gproducingl means: shown Another lthing thatJcan'be readily. seen-l from the curve 23 0f Fig. 6 ;is :that.the'magnetic field is strongest: during i-rthose times when ithesitates on:a plate or anode'land-iszweakest duringithose times ofquick sweep from one anode to another. This is -3true because Fthe s'umofthe r magnetomotive forces are accumulative .when theyraresubstantially in phase, and aresubtractive when they are substantiallyout of phase. it being of course understood that the fast rotationof-the magnetic field takes place when these magnetomotive forces aresubstantially out of phase. In practicing the invention it may bedesirable to have the strongest magnetic fields while the electron beamis being swept from one anode to another. This is true because when themagnetic field is strong a narrow electron beam exists and it isdesirable to have a narrower electron while it is swept from anode toanode whereas a wider electron beam may be tolerated while the electronbeam hesitates or stands still on a particular anode during itsrotation. In view of these considerations it may be desirable to have astrong magnetic field while the electron beam is being swept from anodeto anode and such a construction has been illustrated in Figs. 2 and 3and has been graphically illustrated by the curve 49 in Fig. 5.

The operation of the Fig. 1 structure merely involves an observation ofhow the application of alternating current of fundamental frequencyderived from the generator AC and applied to winding II in combinationwith a triple frequency produced by the frequency multiplier FM! andapplied to the winding I? .may cause step-by-step rotation of theelectron beam 20 in the tube or envelope Hi. This is especially true inthat it is to be understood that a rotating beam electron tube may beused in many situations where fast commutation or circuit switching isto be accomplished. As illustrated, this electron beam 20 is not adouble beam such as would ordinarily be produced by a, magnetic field ofthe type just described concentrating the electron emission from thecathode into a narrow path, that is, a two pole magnetic field. Itshould however be understood that the invention may be applied in thesame way to a tube having a double electron beam. In order to suppressone of the two electron beams that would be inherently produced by a twopoled magnetic field of the type under consideration, the electron tubeI illustrated in Fig. 1 is provided with suppression grids Gs, one foreach anode or plate P. These suppression grids Gs are, as shown,energized electro-statically directly from the fundamental alternatingcurrent frequency supplied by the generator AC and these potentials aresuch that their application to one suppression grid Gs aids the flow ofelectrons to the associated anode whereas the oppositely locatedsuppression grid Gs being exposed to the other end of the electron beamopposes and suppresses the flow of electrons. From this it is readilyseen that as the electron beam 20 rotates, the electrostatic potentialsapplied to the grids Gs also rotate and always suppress one end,.namelythe end not shown, of the two beams whereas they aid electron flow forthe other end, namely. the beam 20, of the two beams that wouldordinarily result. It should be understood that the stator ISI isrotatably positioned on the electron tube l0 so that the relativeposition of the rotating magnetic field may be shifted with respect tothe relative position of the anodes and screen grids as to produce theproper phase of relationship between these elements, the stator ISI ofcourse being locked in position after it has once been moved to theproper phase shifted position. As shown, the stator ISI (Fig. 1) isshownshifted clockwise substantially 45 with respectitoe'zthe thepotential producing the-particular magnetic pole. This has been-thusillustrated because the magnetism actually. lags-the. potentialproducing it and in practice this lag. may be more nearly degrees sothat additional shifting ofthe stator ISI in a clockwise direction maybe necessary.

Since the various voltages applied to the various screen grids Gs shouldhave potentials with respect to ground, .a grounding network includingresistances I 8, l9, 2land 22 has been-provided for the main winding Hwhereas similar grounding resistances 35, 36, 31 and 3B havebeenprovided for the supplemental winding l2. It will be observed that theseresistances i8, l9,-2-I and 22 and 35-38 are connected in star fashionwith the star point connected to. ground as conventionallyv shown- Bythe employment of. these-resistances, a definite voltage gradientexists. between the cathode Ca which is also grounded and the variousscreen grids Gs. Structures-Fig. 2.In Fig. 2 ha'sbeen illustrated anelectron tube [0 of identical construction as that shown in Fig. 1. Thistube is surrounded by a, Gramme type core structure 182 provided with asingle winding 40 instead of the two windings shown in Fig. 1. In thiscasea single phase shifting network comprising the condensers C5 and C6and the resistance-units R5 and. R6 is employed and this phase. shiftingnetwork is fed by the fundamental frequency alternating current-derivedfrom the generator AC and in multiple therewith is also fed byalternating current derived from the frequency multiplier FMZ. Since inthis construction, only one phase shifting network is employed; the lowfrequency alternating current and the high frequency alternating currentapplied to the winding 40 will of necessity rotate in the same, namely,the clockwise, direction and for this reason and reasons already pointedout hereinbefore, the supplemental frequency derivedfrom the frequencymultiplier FM2 must be equal to the fundamental frequency multiplied bythe number of anodes plus one. That is, must be five times that of thefundamental'frequency since a four anode electron tube III has beenillustrated in Fig. 2. The phase splitting network; C5, R5, C6, R6 isdesigned to obtain the desired phase shift for the fundamental frequencycurrent and thus will produce slightly more but less than 90 phase shiftfor the supplemented and higher frequency current. It will thereforeserve-admirably for currents of both frequencies. It will be observedthat a tuned unit ll-42, comprising a condenser 4| and an inductance 42in multiple, is used to pass the low frequency current and block theflow of high frequency current, and

that a similar tuning unit 43-44,- comprising a condenser 43 and aninductance. is employed to pass the high frequency current andblock theflow-of low frequency current. These tuning units 4l42 and 43-44. areresorted .to to allow the flow of current only into the circuits forwhich they are intended and to prevent one source of current frombecominga loader short circuit for the other source of curent.

In oder to properly ground the cathode Ca (Fig. 2) with respect to themidpoint of all of the potentials applied to the winding-.40 and thescreen grids connected thereto, the.' groundnetwork, includingresistance units 85, 46,. 41, and 48, has beenprovided'in-Fig; 2. Thepurpose of this group of resistances 'connectedis'in star rfas'hionihasalreadyibeen explainedin connection vwithzFi ximfi-the drawings.

t0.per.ation.-?Eig.t?2-.-As already pointed out'the fundamental or *lowfrequency-current and the ts'upp'lemental tor high f frequency currentapplied "to the structure of Fig. 2'produees rotating mag- -netic fields:which :rotate 'inzthe same -directi0n because the same phase splittingnet-work ismsed for both alternating currents and also for rea-"sonsheretofore' pointed out, the frequency of the supplementalalternating current is five times that of the fundamental alternatingcurrent frequency. Referring now:to'Fig. :5 ofthe-drawings, let .usassume that the voltage vector is the voltage derived from :thegenerator AC (Fig. 2)

'and'that the voltagevector. 5 is derived from the .tfrequencymultiplier FM2 and that these two voltages are in phase as illustratedin Fig. 5. Since the fundamental frequency is only onefifth that of'theauxiliary frequency let us as- .sume :that an instant of time laterwhen the fundamental frequency has shifted 18 (onefifth of 190) asillustrated by the-vector 52, at which itime'the high frequency-vectorhas shifted to anextent of 90 as illustrated at 53. It is thus seenthatthe magnetic phase rotation produced by the stator 1S2 and-its winding45] has shifted from a position midway between two anodes to,a.;position substantially directly over one anode during .an:.18shiftof the fundamental magnetoimotive force and .that-the sum of themagneto- -m0tive forces was greatest when the speed of magnetic fieldwas greatest, as shown by curve 49 (Fig. 5) .Let us further observe thatduring the next 18 of rotation of'fundamental mag- IIE'EOIIIOHVB forceto the position indicated by the vector $.54, the auxiliary frequencyagain rotates --through an angleof 90 so thatpractically nonetrotationrof magnetic field hasrtaken place inthat the high speed vectorwhen added to the :fundamental vector 54 results in practically no-net-phase. :shift. Letvus'now observe that during the;neXt 18 of.rotation of the fundamental mag- :netomotive force vector as.illustrated by the vecrtor 56 the high speed vector 51 actually rotatesbackwards to a. greater extent so that the magrneticufield does not onlynot advance but actually :rotates in thereverse directioneduring thisonetwentieth of a revolution (18") of the magnetic field. By studyingthe graphic analysis illustrated bythe curve 49 in'Fig. 5 of thedrawings it is readily seen the anodes should be placed at 'points45"displaced from :the-vertical and horizontal lines of the diagram as isalso. true of the Fig. 6 structure.

theFig. 5 diagram the magnetomotive forces are strongest when the fieldshifts forwardly at a high speedwhereas in the Fig. 6 structure 'themagnetomotive forces are the smallest during :such fast-shifting of themagnetic ffield. Conversely the rotating beam isless sharply focusedwhen the electron beam is aimed at an anode in :the Fig. 5 structure.whereas it is most sharply focused When in communication with an nodein the structures the analysis Of'WhiG'h are shown in Fig. 6.

Structure and Operation-Rig. 3.--The embodiment ofithe inventionillustrated in Fig. 3 .is identical to .that illustrated in :Fig. 2except :that the iron stator I83 illustratedinFig. 3 is .a statoremploying a magnetic structure having astmany salient .polesL59 as thereare anodes, :there :being a single coil windin A60 .for eachzsalientcpole .59, .and that .the 'voltages derived from:thersourcea-AC. and are connected It is also readily seen that inseries in Fig. -as=distinguished=from dieing-connected in multiple asthey -are=in' Fig. In the Fig. *3 structure there are provided two-by-pas's tuning units 61- 62 and 63- 64. The tuningunit including thecondenser -61 and the inductance 62 in multiple has electrical constantssuch that it permits the 'flow of "low frequency current derivedfrom-the generator A'C but blocks=the now of high 1 frequencycurrent-derived front-the frequency multiplier -FM3-and the tuningunitfi -64 comprising acondenser -63 and an induc- -tance B4 in multiple,has electrical -constants such as'to block the-flow-oflowfrequency-current deri-ved 'from the generator AC and' to' bypass thehigh frequency current derived from the frequency multiplier -FM3. Sincethe operation of "the structures-illustratedin'Figs. 2-and 3 areidentical no "specific operation or discussion "of --vector diagrams-orother graphicalanalysis necd be given except'to say that the analysisillustrated by'curvemof Fig; 5 isapplicable.

Structure and Operatiom- Fig. 4.The -ap- 'paratus illustrated in Fig. 4is very-similar to that illustrated in 'Fig. 1, these-devicesdiffering-particularly in "that only one winding i5 is-contained on thestator IS'4. This winding 65-is supplied by alternating current from--two independent phase shifting and grounding networks similar to thoseillustrated in Fig. 1, these networks being supplied by alternatingcurrents of dif- 'ferent frequencies as already explained in-con-'nection with Fig. *1 of-the drawings. "It should be observed that atuning unit including-tho condenser H and inductance "72 has-beenprovided in *Fig. 4 to pass alternating current of low frequency derivedfrom the alternating current source AC, and to block the flowof'highfrequency current derived from the frequency-multiplier FM4. 'Thecondenser 1! and inductance "12 of this unit ll- 12 of coursehaveelectrical constants so as to performboth a"tuning* funetion for thelow-frequency current and a-blockingfunction for the high frequency:current. 'It should alsobe noted that COIldGl'lSGI'SflB and "have beenprovided to ltune the transformers T11 and T12 respectively so that= thei -two-alternating current sources are-properlyisolated from each otherby a :suitable 'tunedunit. That is, the-secondary windings ofi'transformers 'Ih l and Tr? are tuned to passihigh frequencycurrent-arid block the flow oflow frequency current. In-all otherrespects the structure of Fig. A i is similar 'to that-of Fig. 1 and:since both of' these struc- "tures produce 'the same operating resultsit is unnecessary :to specifically discuss-the operation ofthe-apparatus illustrated in Fig. :4. It -may, however, be -pointed :outthat the f unctional 'resultsaof the Fig. 4- structure aregraphicallyillustrated by the curve n ina-Fig. 6 of the drawings, thefrequency of the high frequency current being "three-atimes the:frequency of the ilow frequencycurrent.

It-should be understood-that independent gen- *erators connected to:thesamexshaft or interconnected by gear connections may be :used instead'Of the generator- A0 andllits associated frequency multiplying unit'-FM4 illustrated. In :th-isconnection= it shoulds-bel borne. inmindrthat: thee-two alternating currents =must haveaaconstant and fixedfrequency ratio. .It should however %be nnderstoodrthat any: desiredvoltagearrelaticnship :within limits:.mayibetemployed' but:theyoltageaofthe higher frequency energy :per-unitnofxim- :pedanceshould alwaysbe'tlws than 1. the lvoltage :ofrthe low:- frequency energy.

I t is further desired to point out that the rotate'lectron-beam tube ofthe'present invention lends itself particularly well to systems wheresuch tubes are -connected in-cascadeor in tandem as is the case forsystemsdllustrated,inthe prior filed pending application of Field} andWight, ser. No. 599,328,,fi1 3d, June re, 1945, which has resulted inPatent No 2,488,431 dated August 31, 1 948. In that patenttwo rotatingbeam electron tubes are so connected in cirou its and are so controlledthat the electron beam in one tube makes a complete revolution while theelectron beam in another tube sweeps from engagement with one anode toengagement with another anode. In such a system it therefore becomesimportant that as little time as possible be lost by the beam of theslow tube in moving from one anode to the next anode in that it shouldbe in communication with any particular anode during substantially theentire rotation of the electron beam of the fast tube and should thenshift very quickly to another anode. The importance of rotating electronbeam tubes whose rotating beam rotates in step-by-step fashion withvarying sharpness of focusing should now be apparent not only whereindividual tubes are used separately but also where such tubes areconnected in tandem.

Briefly stated the rotating beam electron tube, if used in accordancewith the present invention, may be used to transmit a plurality oftelephone conversations simultaneously but on the time allotment basisor may be used in a Synchronous type control or indication system bycontrolling simultaneously or in sequential relationship a plurality ofdevices from a distant point either over line wires or through themedium of space radiation, and performs these functions more emcientlyand more accurately than do mechanical devices.

Having thus shown and described numerous ways and means for causing anelectron beam in an electron tube to rotate in step-by-step fashion andhow to more sharply focus this electron beam either as it is moved fromanode to anode, or as it hesitates on an anode, it is desired to beunderstood that these various examples in which the present inventionmay be practiced have merely been resorted to for the purpose ofexplaining the nature of the invention and its underlying principles andthat various other gara e structures may be employed to accomplish thesame or similar results and it should be understood that variouschanges, modifications and additions may be made in practicing theinvention without departing from the spirit or scope thereof except asdemanded by the scope of the following claims.

What I claim as new is:

1. In an electronic translating device, the combination with a sealedenvelope, a cathode near the axis of said envelope, a plurality ofanodes surrounding said cathode, suppression grids between the cathodeand the anodes, and an electromagnet having a multiple phase windingsurrounding said anodes, of circuit means for energizing said windingsimultaneously by multiple phase alternating currents of two differentfrequencies, one frequency being a multiple of the other, whereby theresultant magnetic field rotates in a step-by-step manner, and means forelectrostatically energizing said suppression grids with respect to saidcathode from both of said frequency currents, whereby the electronsemitted by saidicathodei are formed into a racist can;

rotatedfromanode to anode in accordanceewith] the rotation ofv saidresultant magnetic ea-, ,2..I n an electronic translating,device,-.the,com:. bination with a sealed envelope, a cathodenear, theaxis of said. envelope, a plurality-of anodes, circumferentiallydisposed about said cathode suppression grids between the anodes andthe; cathode, and a two-phase electrornagnet s rounding-saidanodes, ofcircuit means for energizing said electromagnet by two-phase energy fromtwo diiferent frequency currents simultaneously, one frequency being amultiple of the other, whereby the resultant magnetic field rotates in astep-by-step manner, and means for electrostatically energizing each ofsaid suppression grids with energy of varying potential with respect tosaid cathode in synchronism with said rotating field whereby theelectrons emitted by said cathode are concentrated into a beam extendingradially from said cathode and scanning the respective anodesstep-by-step in synchronism with the rotation of said resultant magnetic field. v

3. A rotating beam tube organization comprising, a centrally locatedcathode in an evacuated envelope, a plurality of anodescircumferentially disposed about said cathode, a suppressor grid betweeneach anode and the cathode, a source of two-phase alternating current ata particular frequency, a source of two-phase alternating current at amultiple frequency of said particular frequency, circuit means forapplying each of said frequency currents to said suppressor gridselectrostatically in a manner to render such grids alternately positiveand negative with respect to said cathode, a two-phase electromagnetsurrounding said anodes, circuit means governing the energization ofsaid electromagnet from both of said sources of alternating currentsimultaneously,whereby the electrons emitted from the cathode areconcentrated into beams by the respective rotating fields ofsaidelectromagnet and a single radial beam of increased concentration isformed-each time that the two frequencies are in phase.

4. In a rotated beam tube organization of the character described, thecombination with a sin-, gle cathode centrally located in an evacuatedenvelop'e and a plurality of anodes circumferentially located about saidcathode, of a two-phase electromagnet surrounding said anodes, andcircuit means governing the energization of said electromagnet whereinrotating fields of different frequencies are set up in saidelectromagnet by the energization of said electromagnet with two-phasealternating current of two different frequencies, one frequency being amultiple of the other, and the lower frequency current pro-- viding arelatively stronger field than the higher frequency current, whereby theelectrons are concentrated into beams by the respective rotatingmagnetic fields, a more concentrated beam being provided by the fieldset up by the lower frequency current, and that beam beingintermittently concentrated to a still greater extent when bothfrequency currents are substantially in phase.

5. A rotating beam tube organization comprising, a single cathodecentrally located in an evacuated envelope, a plurality of anodescircumferentially located about said cathode, a two-phase electromagnetsurrounding said anodes, circuit means governing the energization ofsaidv electromagnet wherein said electromagnet is enermamas 11 gizedsimultaneously by two- -phase elternati g currents of two difierentfrequencies, one imquengybejing a multiple of the other, whereby theelectrons emitted from the cathode are'coneentra-tefl into beams by therespective rotating fields of sa-id'el'ectromagnet in response toenergization simultaneously by the two different frequency currents anda single beam of increasingc'oncentration formed each time that the twofrequencies are in phase.

JOHN C. OBRIEN.

BEFERENEES CITED UNITED STATES PA'I'ENTS'

